The Deformation Mechanism And Shape Design Of Cylindrical Shell Filled With Medium Under Lateral Explosion Loading

Cylindrical shell structure is a common structural unit in the engineering field,there always involves the dynamic response of shell under lateral impact load in the application process.For instance,the submarines or large ships suffered from the impact of underwater explosions,the missile intercepted by the impact of explosion shock waves,and the design of deformable warhead.This dissertation based on the research background of deformable warhead,and the deformation laws of cylindrical shells filled with medium under lateral explosion loading were studied.Through the combination of theoretical analysis,numerical simulation and experimental study,the deformation mechanism and optimization design of shell shape were obtained.The main achievements of this paper are as follows:1)Based on the ideal rigid-plastic theory and plastic hinge theory,the theoretical analysis model of the cylindrical shell under lateral explosion loading was established,and the engineering of theoretical analysis model was achieved through the Matlab.In addition,the ? parameter which is used to measure the approaching degree of deformation shape closing to the D shape,as well as the ?parameter which is used to measure the width of deformation shape,were proposed for the first time.These two criteria can provide a criterion for shell shape deformation.2)Due to the complexity of the factors affecting on the shape of shell deformation,this paper is based on the orthogonal experiment design method to obtain simulation program,then the numerical simulations were carried out.The influence rule of each factor to the deformation shape of the shell was obtained.The main and sub factors of the deformation shape of the shell are as follows: width of deforming charge— >thickness of deforming charge — >thickness of inner shell — >type of shell combination—>thickness of outer shell.This conclusion can provide references for the structural design of cylinder shell filled with medium.3)In order to verify the rationality and accuracy of the numerical simulation,three factors(type of medium,center hole,width of deforming charge)were selected randomly to verify the numerical simulation results.The numerical simulation results are in good agreement with the experimental results which indicates the scientificity and reasonability of the numerical simulation methods.4)To verify the optimal scheme obtained by the orthogonal experiment design,16 groups of numerical simulations were carried out.The result showed that the ? of the optimal scheme is the smallest comparing with the 16 groups of conditions,and the ? of the optimal scheme value falls within the optimal evaluation interval range.The results are in accordance with the predicted results.In addition,the relationship between the width of deforming charge and the value of ? was established,which can provide a fast way to calculate the width of deforming charge under different ? values in the case of a given initial shell size.Therefore,the design method proposed in this paper can provide references for the optimal design of cylindrical shell structure.